Fatty acids, sterols, phenolic compounds, and carotenoid changes in response to dietary inclusion of Ulva clathrata in shrimp Litopenaeus vannamei broodstock

Changes in lipid reserves as a result of supplementing 3.4% Ulva clathrata meal in the diet (based on dry weight of all ingredienta) for Litopenaeus vannamei broodstock were evaluated in a commercial larval laboratory. The profile of fatty acids, sterols, carotenoids, and phenolic compounds in the gonad, hepatopancreas, and muscle of females with unilateral ablation was analyzed. Shrimp fed the Ulva supplemented diet had significantly higher proportions of arachidonic acid (20:4n-6) in the acylglycerides of mature gonads (84% increase) compared with mature controls. In the phospholipids of mature gonads, there was a 30% increase of 18:3n-3, 13% increase of 20:4n-6, and 10% of docosahexaenoic acid (22:6n-3) in Ulva-fed shrimp compared with controls. 22:6n-3 also increased 51% in the lipid reserves of hepatopancreas of Ulva-fed shrimp compared with controls. Carotenoids increased by 43% in the gonads and fivefold in the hepatopancreas of mature females fed Ulva. The proportion of fucosterol and isofucosterol went from undetectable in controls to 0.3 and 0.2%, respectively, in shrimp fed the algae. No significant differences were found in muscle. Phenolic compounds in the gonad were higher in mature gonads compared with immature, but no significant differences were found in relation to Ulva consumption. Carotenoids and phenolic compounds present in Ulva might be acting as antioxidants of highly unsaturated fatty acids (HUFAs), increasing the proportion of 20:4n-6 and 22:6n-3, but other mechanisms associated to these compounds and to fucosterol can be synchronizing oocyte maturation and increasing transport of HUFA during vitellogenesis, and together, they are further impacting the reproductive performance of shrimp.